-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 03/23/11 09:04, Bernd Schmidt wrote: > On 03/23/2011 04:03 PM, Jeff Law wrote: >> On 03/23/11 08:55, Bernd Schmidt wrote: >>> The first basic block contains insns to move incoming argument registers >>> to pseudos. When these pseudos live across calls, they get allocated to >>> call-saved registers. This in turns disables shrink-wrapping, since the >>> move instruction requires the prologue (saving the call-saved reg) to >>> occur before it. >> >>> This patch addresses the problem by moving such moves downwards through >>> the CFG until we find a place where the destination is used or the >>> incoming argument is clobbered. >> FWIW, downward motion of the moves out of arg registers (or loads from >> arg slots) is definitely a good thing. This was a regular source of >> unnecessary register pressure leading to spills in codes I've looked at. >> >> I hope your sinking code works better than the quick and dirty one I >> wrote but never contributed. > > Sadly I'm doing it after register allocation, so it wouldn't help with > your problem. That'll still help :-) I can run your sinking code, then use the existing IRA callbacks to attempt to allocate any pseudos which didn't previously get hard regs. It's actually quite easy.
jeff -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJNig9CAAoJEBRtltQi2kC7I3kIAJ6manYH+/ZFcdQwfxroN0im U0Oc18wbEz5VZg3SXnw7wEm6uRPKxYLS9/t2bMo0xLY2cHCWZx2QLH9g9O09lnUv EU5lG46H7oIJuwhuC8osvsJUbLfQL5PkGQJdF4mfab1uk/Et5RSo8wfna7HDhTXU b8WJltvS2ZJQIggSFxXtM101eq2/oiiU286WC8wdqlbq0lgWotBcxhHNuZeO/LEj NeGX91kcFDl8RcwQNeT2a2G+JC0i5tc1S4C3d9pGgUiqDWpmjx74WrlRpzpkF8EF 7kfYm48xY5hPcmUcZ7vJU5Aq3Ik7U2rM6aO9H3dYoFTAOmcgs22Rbj6FoDMrUXE= =N5L7 -----END PGP SIGNATURE-----
